drm/i915/gvt: fix dead locking in early workload shadow

As early workload scan and shadow happens in execlist mmio handler,
which has already taken vgpu_lock. So remove extra lock taking here.

Fixes: 952f89f0 ("drm/i915/gvt: Wean off struct_mutex")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/gvt/scheduler.c

@@ -1584,9 +1584,7 @@ intel_vgpu_create_workload(struct intel_vgpu *vgpu, int ring_id,
 	 */
 	if (list_empty(workload_q_head(vgpu, ring_id))) {
 		intel_runtime_pm_get(&dev_priv->runtime_pm);
-		mutex_lock(&vgpu->vgpu_lock);
 		ret = intel_gvt_scan_and_shadow_workload(workload);
-		mutex_unlock(&vgpu->vgpu_lock);
 		intel_runtime_pm_put_unchecked(&dev_priv->runtime_pm);
 	}